In researching the often unsavory but not necessarily illegal trade of exotic animals, Green tackled a subject most people don't even want to think about, let alone read about in detail. But his is a story that needs to be told, because how we treat nature's creatures reflects upon our humanity.

Green tracks traders as they sneak exotic and sometimes endangered animals across state lines, where they are either auctioned to the highest bidder or resold to oft-times unlicensed dealers. The animals many times end up in substandard roadside zoos, in the entertainment industry, at commercial game preserves, at meat processing plants, or with unqualified families who try to keep them as pets.

Baseball star Jose Canseco, for example, owned a six-foot mountain lion named Buffy that was seized by animal officers after it escaped from his garage in Florida and joined a neighborhood pool party.

The animals aren't always mistreated intentionally, but inexperienced owners or those lacking enough money can easily neglect the food and space needs of animals that live naturally in the wild.

In other cases, the treatment is cruel, part of the handling by dealers who see animals as just another item to trade for money. Green describes large tigers short-chained in the back of garages or near dumps, birds crowded into tiny cages with sick or dead cellmates and other animals beaten, abandoned, or nearly starved.

Green also speaks of the dangers of human and wild animal interactions. Those not handled properly can harm or kill people. Some animals, particularly monkeys, can carry diseases.

The animals on the trading route are not necessarily ill-gotten. Often, they come from the nation's zoos, outcast because they are considered surplus or old.

Last spring's cute baby giraffe has worn out its welcome by the following spring when zoo visitors crowd to see this year's new baby. On one single day alone, the American Zoo and Aquarium Association was trying to get rid of 600 mammals, about 400 reptiles, thousands of fish, and hundreds of invertebrates, Green writes.

Several publications, including Animal Finders' Guide, list animals for sale, such as a 19-year-old giraffe for $17,500 and Japanese macaque monkeys for $6,000. Michael, a once-adored 11-month-old giraffe from Washington, D.C.'s National Zoo, was sold to a dealer who in turn sold it to Animal Kingdom Pet Store &amp; Zoo, a roadside zoo in New Jersey. There, Michael died 16 months later, when an older giraffe broke his neck.

The owner of Animal Kingdom is Burton Sipp, who Green writes is a "self-described animal-rights activist who was once characterized by a superior-court judge as 'a man whose own lack of integrity is unimpeachable.' "

While Green says curators at the National Zoo have good reason to shy away from dealers like Mr Sipp, "when you're trying to dispose of a giraffe, something very disquieting soon becomes apparent: If there are no legitimate takers, you may have nowhere else to turn."

Respected zoos don't like to acknowledge this part of their business. And the animal dealers and traders are elusive. There are loopholes in state and federal laws that can make it almost impossible to track an animal's ownership. "Captive-bred wildlife is by and large no one's responsibility, no one's jurisdiction, and really no one's concern," he writes.

Green and his team sifted through about 2 million state health certificates from 27 state departments of agriculture to collect the 3,000 relating to exotic species. He collected thousands of records from other sources, including cases of alleged violations of the Animal Welfare Act and stud books maintained at zoos accredited by the American Zoo and Aquarium Association. He also conducted hundreds of interviews.

The book falls somewhat short in naming sources of information about the behavior of dealers. But, of course, illegal traders don't want to talk, and people who know of their activities often are reticent to go on the record.

Green at times comes dangerously close to sounding like the radical animal activists who throw paint at people wearing fur coats. His descriptions of animal abuses are compelling and mind-numbing enough without loaded language such as "freakish acts of violence" and "ethical travesty."

However, Green does justice to documenting the sad relationship between people and the animals they keep for pleasure. Unlike the horse in "Black Beauty," Green's animals rarely find a happy ending. Perhaps this book will help change that.